JP3065041B2 - Semiconductor device film forming method and film forming apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for forming a film on a substrate such as a semiconductor substrate using a liquid containing an organic metal in a semiconductor device manufacturing process. About.

[0002]

2. Description of the Related Art In recent years, in the process of manufacturing semiconductor devices, demands for high integration and miniaturization of semiconductor devices have been increasing. In order to meet such demands, aluminum-based wiring materials used in a film forming process have been used. From copper to copper.

As a method of forming a film using such a material containing copper, for example, (hfac) Cu ⁺¹ (tmv
A method of forming a thin film by vaporizing an organic metal such as s) (liquid at normal temperature and normal pressure) and introducing it into a processing chamber, and performing a thermal decomposition reaction on a substrate disposed in the processing chamber is known. I have.

[0004]

In a film forming method using a liquid containing an organic metal as described above, an organic metal-containing material is formed on the entire inside of a hole or a groove such as a contact hole finely processed on the surface of a semiconductor substrate. There is a strong demand that a liquid be uniformly poured to form a film having excellent embedding properties without generating voids.

An object of the present invention is to provide a film forming method and a film forming apparatus for a semiconductor device which can form a film having excellent void-filling properties.

[0006]

In order to achieve the above object, the present invention provides a method of forming a film by depositing a liquid containing an organic metal on an object to be processed disposed in a processing chamber and causing a thermal decomposition reaction. Performing a film forming method of a semiconductor device,
First, a solvent to be mixed with the organic metal is deposited on the workpiece,
After that, a method for forming a film of a semiconductor device is provided, in which a liquid containing an organic metal is attached to an object to be processed.

[0007] When a liquid containing an organic metal is adhered onto the object to be processed in a state where the surface of the object to be processed is wetted in advance with the solvent mixed with the organic metal, the liquid is applied to the solvent to which the liquid has previously adhered. Familiar and even throughout the whole,
The liquid containing the organic metal flows evenly into the finely processed holes and grooves on the object to be processed. Therefore, a void is hardly present inside the fine pattern, and a film having excellent filling properties can be formed.

In the method for forming a film of a semiconductor device,
Preferably, as the liquid containing an organic metal, a mixture of an organic metal and a solvent is used. As a result, the liquid used for film formation only requires a solvent mixed with the organic metal,
Equipment such as a tank for storing liquid can be reduced, and cost can be reduced.

For example, a ketonato metal complex of copper is used as an organic metal, and an aliphatic saturated hydrocarbon is used as a solvent mixed with the organic metal.

[0010] In order to achieve the above object, the present invention provides a semiconductor device in which a film containing an organic metal is deposited on an object to be processed disposed in a processing chamber and is thermally decomposed to form a film. A film deposition apparatus, a solvent attaching means for attaching a solvent mixed with the organic metal on the object to be processed,
An organic metal-containing liquid adhering means for adhering a liquid containing an organic metal on the object to be processed, a solvent adhering means for adhering a liquid containing the organic metal onto the object after adhering a solvent onto the object, and A film forming apparatus for a semiconductor device, comprising: a control unit that controls an organic metal-containing liquid applying unit.

By providing the means for applying the solvent, the means for applying the organic metal-containing liquid, and the control means as described above, the above-described film forming method can be carried out, and a film having no voids and excellent filling properties can be formed. It becomes possible.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 schematically shows a first embodiment of a film forming apparatus according to the present invention. In the figure,
The film forming apparatus 10 includes a processing chamber 12 in which a semiconductor substrate W to be processed is placed.
The turntable 14 which is the support means is disposed. The turntable 14 supports the substrate W by a suitable means such as a vacuum chuck or the like, and is rotationally driven by a drive motor 16 installed outside the processing chamber 12. Although not shown, the turntable 14 has a substrate W
Is provided with a ring-shaped clamp member for clamping the edge of the ring. The reason for providing this clamp member is that when film formation is performed at the edge of the substrate W, problems such as the generation of particles occur. In the processing chamber 12, a plurality of heating lamps 18 such as halogen lamps for heating the substrate W placed on the turntable 14 are provided.

The film forming apparatus 10 includes a liquid deposition device 20 for depositing a mixture of an organic solvent and an organic metal on an organic solvent on the surface of the substrate W, and a control device 22 for controlling the liquid deposition device 20. Have. Here, heptadecane is used as the organic solvent, and (hfac) Cu ⁺¹ (tmvs) which is liquid at normal temperature and normal pressure is used as the organic metal.

The liquid deposition device 20 supplies a first tank 24 for storing the organic solvent, a second tank 26 for storing the organic metal, and a first tank 24 and a second tank 26. Mixing tank 32 connected via pipes 28 and 30 and mixing tank 3
And a supply pipe 38 which is connected to a supply pipe 34 and a joint 36 such as a hose and partially extends to the inside of the processing chamber 12, and a nozzle 40 which extends horizontally from the upper end of the supply pipe 38 and has a downward end. And a bypass pipe 42 connecting the supply pipe 28 and the supply pipe 34.

In the mixing tank 32, an organic solvent (heptadecane) stored in the first tank 24 and an organic metal ((hfac) Cu ⁺¹ ) stored in the second tank 26 are rotated by a drive motor 44. (Tmvs)) and a pair of mixing rolls 46 are arranged.

The supply pipe 38 is driven to rotate by a drive motor 48, so that the tip of the nozzle 40 can rotate about the axis of the supply pipe 38. The drain tube 50 is disposed immediately below a predetermined position in the movement path of the tip of the nozzle 40.
Is collected in the drain tube 50 and can be reused.

The supply pipes 28 and 30 are provided with on-off valves 52 and 54 and a mass flow controller (MFC) 5 for adjusting the supply flow rate of the organic solvent from the mixing tank 32 side.
6 and 58 are provided. The supply pipe 34 is provided with an on-off valve 60, and the supply pipe 42 is provided with an on-off valve 62.
Is provided. These on-off valves 52, 54, 6
Numerals 0 and 62 are electromagnetic types, and are controlled by the control device 22. The MFCs 56 and 58 are adjusted by a signal from the control device 22 to supply a predetermined amount of an organic solvent and an organic metal.

In the above liquid applying apparatus 20, the first tank 24, the supply pipe 28, the MFC 56, the on-off valve 52, the bypass pipe 42, the on-off valve 62, the supply pipe 34, the joint 3
6. The supply pipe 38 and the nozzle 40 constitute a solvent adhering means for adhering an organic solvent (heptadecane) mixed with the organic metal onto the substrate W, and the first tank 24, the supply pipe 28, and M
FC56, on-off valve 52, second tank 26, supply pipe 3
0, MFC 58, on-off valve 54, mixing tank 32,
Supply pipe 34, on-off valve 60, joint 36, supply pipe 3
8. The nozzle 40 constitutes an organic metal-containing liquid applying means for applying a liquid containing an organic metal (a mixture of heptadecane and (hfac) Cu ⁺¹ (tmvs)) onto the substrate W.

When the supply of the organic solvent is instructed by, for example, a manual switch (not shown), the control device 22 outputs an off signal to the opening / closing valves 54 and 60 so as to apply only the organic solvent onto the substrate W. An ON signal is output to 52 and 62. Then, for example, when a built-in timer detects that a predetermined time has elapsed, the above state is opened and closed in order to apply a mixture of an organic metal and a solvent (hereinafter, referred to as a film forming solution) onto the substrate W. An off signal is output to the valve 62 and the on-off valve 5
4 to output an ON signal.

A film forming method for forming a thin film on the surface of the substrate W using the film forming apparatus 20 configured as described above will be described.

First, the substrate W is placed on the turntable 14 by a transfer device (not shown), and then the drive motor 16
To rotate the turntable 14 at a predetermined rotation speed. At this time, in order to prevent oxidation and other reactions on the surface of the substrate W, it is preferable to supply an inert gas such as a nitrogen gas into the processing chamber 12 so that the processing chamber 12 is kept in an inert gas atmosphere.

The substrate W used here is applied to a dual damascene process having a multilayer structure as shown in FIG. The substrate W has a silicon oxide (SiO ₂ ) layer 64 formed on a silicon (Si) base 62 and a tantalum (Ta) barrier metal layer 6 thereon.
6 are formed (FIG. 2A). The reason why the barrier metal layer 66 is provided is that, when the film forming solution is applied on the substrate W, the copper (Cu) component in the film forming solution is contained in SiO ₂ and further in S _2.
This is to prevent diffusion into i. The barrier metal layer is not limited to the above Ta, but may be tantalum nitride (Ta).
N), titanium nitride (TiN), tungsten nitride (W
N).

Subsequently, the control device 22 controls the on-off valve 52,
When 62 is turned on, the organic solvent (heptadecane) stored in the first tank 24 is sent to the nozzle 40 via the supply pipe 28, the bypass pipe 42, and the supply pipes 34 and 38, and only the organic solvent from the tip thereof. It is dripped. At this time, since the turntable 14 is rotating at a relatively high speed, the organic solvent applied on the substrate W spreads radially outward by centrifugal force, and the heptadecane layer 68 is formed.
(B)).

Heptadecane, which is an organic solvent, has good wettability (degree of spread) with respect to the Ta film constituting the lower barrier metal layer 66, and thus can be efficiently spread over the entire surface of the substrate W. In addition, heptadecane sufficiently flows into the inside of the hole or the groove, and good coverage is formed.

At this time, after the turntable 14 or the substrate W itself is vibrated by ultrasonic waves or the like, or heptadecane is applied on the substrate W, a sponge-like roller pad or the like is brought into contact with the substrate W to horizontally By moving in the direction, heptadecane can be more efficiently spread over the entire surface of the substrate W.

Subsequently, when the control device 22 turns off the on-off valve 62 and turns on the on-off valves 54 and 60,
Heptadecane stored in the first tank 24 and (hfac) Cu ⁺¹ (tmv) stored in the second tank 26
s) is supplied to the mixing tank 32 via the supply pipes 28 and 30, and a film forming liquid obtained by mixing them is generated by the mixing roll 46.
And 38 to the nozzle 40 and is dropped from the tip.

At this time, since the previously applied heptadecane is a solvent, the film-forming liquid easily conforms to the heptadecane layer 68, and efficiently spreads over the entire surface of the substrate W using the heptadecane layer 68 as a coating aid. The deposition liquid is attached with a uniform film thickness and film quality over the entire period. Further, since heptadecane is already attached to the side surfaces of the holes and grooves, the film-forming solution flows evenly into the inside of the holes and the like, and the film is buried without generating voids. Then, the film forming liquid diffuses into the heptadecane, and the heptadecane layer 68 becomes a form absorbed by the film forming liquid. That is, the heptadecane layer disappears, which is equivalent to the case where the film-forming liquid layer 70 is formed immediately above the barrier metal layer 66 (FIG. 2).
(C)).

Thereafter, the heating lamp 18 is turned on to heat the film-forming liquid adhered on the substrate W. Then, (hfac) Cu ⁺¹ (tmvs) in the film forming solution undergoes a thermal decomposition reaction, and copper is deposited on the surface of the substrate W to form a thin film 72 (FIG. 2D). (Hfac) Cu ⁺¹ (tmvs)
Is as follows.

[0030]

Embedded image

The Cu ⁺² (hf
Since ac) ₂ and tmvs are gasified by the internal temperature of the processing chamber 12 during the thermal decomposition reaction, they are discharged from the processing chamber 12 by an exhaust pump (not shown).
Heptadecane, which is an organic solvent, is also vaporized and discharged by heat and does not remain on the substrate W.

As described above, in the present embodiment, heptadecane as an organic solvent is first applied onto the substrate W to wet the surface of the substrate W in advance, and then heptadecane and the organic metal (hfac) Cu ^{+ 1} (tmvs) is applied to the substrate W, so that the film-forming solution is adapted to heptadecane and efficiently spreads over the entire surface,
It will evenly flow into holes and grooves. Therefore, burying can be performed without generating voids inside the fine pattern, and a film having a better burying property can be formed than when the film forming solution is directly applied onto the substrate W without previously wetting the surface of the substrate W. It is considered possible.

Further, since the film quality becomes uniform over the entire surface of the substrate W, a part of the film does not peel off.
The adhesion to the substrate W is improved.

Further, before applying the film forming liquid, the substrate W
The same heptadecane as the solvent used for forming the film-forming liquid is used as the organic solvent for keeping the film wet, so that the number of equipment such as tanks and pipes can be reduced to a minimum and cost can be reduced.

In this embodiment, heptadecane is applied onto the substrate W, and then heptadecane and (hfadec) are applied.
c) The film forming liquid mixed with Cu ⁺¹ (tmvs) is applied on the substrate W. However, the present invention is not limited to this. The coating liquid is coated with heptadecane and then coated with (hfac) Cu ⁺¹ (tmvs).
You may apply only.

As the film forming solution, a mixture of (hfac) Cu ⁺¹ (tmvs), which is one of copper ketonato metal complexes, and heptadecane, which is one of aliphatic saturated hydrocarbons, is used. However, as the organic metal, (hfa
c) An organic metal other than a copper ketonato-based metal complex such as Cu ⁺¹ (teovs) or a copper ketonato-based metal complex can be used when forming another material. Also,
Regarding organic solvents for copper ketonato metal complexes,
Other aliphatic saturated hydrocarbons such as pentadecane, hexadecane, and octadecane can be used, and other solvents can be used for organic metals other than the ketonato metal complex of copper. In this case, a material that satisfies the conditions of good wettability to the underlying material, easy diffusion of the organic metal, and no adverse effect when subjected to a thermal decomposition reaction is preferable.

Further, in the liquid applying device 20, a solvent attaching means such as a first tank 24, a supply pipe 28, an MFC 56, an on-off valve 52, a supply pipe 34, a joint 36, a supply pipe 38, a nozzle 40 and an organic metal-containing liquid are attached. Although a common component exists between the means and the means, the solvent attaching means and the organic metal-containing liquid attaching means may all be constituted by different members.

Although the substrate W is supported on the turntable, the means for supporting the substrate W is not limited to the turntable but may be a fixed type that does not rotate.

The present invention can be applied to any apparatus that forms a film using a liquid containing an organic metal, such as a CVD apparatus using a liquid containing an organic metal as a material.

[0040]

According to the present invention, when a film is formed using a liquid containing an organic metal, a void is hardly generated in a finely machined hole or groove on a workpiece.
It becomes possible to form a film having an excellent embedment property.

[Brief description of the drawings]

FIG. 1 schematically shows an embodiment of a film forming apparatus according to the present invention.

FIG. 2 shows a procedure for forming a film on a semiconductor substrate by a film forming method according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Film-forming apparatus, 12 ... Processing chamber, 14 ... Turntable, 20 ... Liquid deposition apparatus, 22 ... Control apparatus, 24 ...
1st tank, 26 ... 2nd tank, 32 ... mixing tank, 28, 30, 34, 38 ... supply piping, 40 ... nozzle, 42 ... bypass piping, 52, 54, 60, 62 ... opening / closing valve, W ... semiconductor substrate (Object to be processed).

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroyuki Yarita 14-3 Shinizumi, Narita City, Chiba Pref. Nogedaira Industrial Park Inside (Applied Materials Japan Co., Ltd.) (72) Inventor Tsune Aida 14-3 Shinizumi Narita City, Chiba Prefecture Applied Materials Japan Co., Ltd. (72) Inventor Naomi Yoshida 14-3 Shinsen, Narita City, Chiba Pref. Applied Materials Japan Co., Ltd. (56) Reference No. JP-A-53132 (JP, A) JP-A-9-45773 (JP, A) JP-A-8-274012 (JP, A) JP-A-9-302471 (JP, A) JP-A-10-140352 (JP, A) JP-A-10-135154 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 21/288 C23C 18/02 H01L 21/3205

Claims (4)

(57) [Claims] 1. An apparatus according to claim 1, wherein (hfac) Cu ⁺¹ (tmvs) and (hfa)
c) A method for forming a film of a semiconductor device, wherein a liquid containing an organic metal selected from the group consisting of Cu ⁺¹ (teovs) is deposited and thermally decomposed to form a copper film, wherein the organic metal solvent Forming a liquid containing the organic metal on the object after depositing an aliphatic saturated hydrocarbon on the object. 2. The method according to claim 1, wherein the liquid containing the organic metal is a mixture of the organic metal and the solvent. 3. The method according to claim 1, wherein the solvent is selected from the group consisting of heptadecane, pentadecane, hexadecane, and octadecane. 4. A method according to claim 1, wherein (hfac) Cu ^{+ 1} (tmvs) and (hfa)
c) A film forming apparatus for a semiconductor device, wherein a liquid containing an organic metal selected from the group consisting of Cu ⁺¹ (teovs) is deposited and subjected to a thermal decomposition reaction to form a film of copper. A solvent adhering means for adhering an aliphatic saturated hydrocarbon as a solvent for the organic metal; an organic metal-containing liquid adhering means for adhering a liquid containing the organic metal on the object to be processed; A semiconductor device comprising: a control unit that controls the solvent adhering unit and the organic metal-containing liquid adhering unit so that the liquid containing the organic metal is adhered onto the object after being adhered on a body. Device deposition equipment.